The present invention relates to annuloplasty rings or devices for use in heart surgery, and more particularly to novel annuloplasty rings or devices and methods for their use in minimally invasive heart valve replacement or repair surgery. Most particularly, this invention relates to novel annuloplasty rings or devices for use in mitral valve replacement or repair surgery.
Human heart valves, such as mitral and tricuspid valves, are sometimes damaged by disease or aging such that the valves no longer properly function. In such cases, heart valve replacement surgery is often indicated. Heart valve replacements and prostheses have been used for many years and many improvements in both the functionality and ease of implantation have been made thereon over time. As used herein, the term xe2x80x9cheart valve replacementxe2x80x9d is intended to include any mechanical valve, tissue valve, or other device that may be attached to any annulus of a heart be means of a sewing ring. In general, the heart valve comprises a valve body providing a blood flow passageway and oclude means mounted on the valve body for opening and closing the passageway. The valve body has an external, circumferential outer surface. Its dimensions are slightly smaller than the inner surface of the sewing ring implant. This facilitates the valve""s body""s mating with the inner surface of the sewing ring implant.
Examples of such heart valve replacement apparatus and methods for implanting such heart valve replacement apparatus have been disclosed in U.S. Pat. Nos. 5,071,431; 4,863,460; 4,743,253; 4,655,773; 4,364,126; 4,204,283; 3,898,999; 3,996,623; 3,859,668; 3,534,411; and 3,143,742. Each and every one of the references cited above is hereby incorporated by reference into this application in their entireties to better describe the state of the art.
In some cardiac valve operations, an annuloplasty ring or valvuloplasty ring is used in the repair of the damaged valve, in order to advantageously avoid, in many cases, heart valve replacement. Examples of such annuloplasty rings or valvuloplasty rings have been disclosed in U.S. Pat. Nos. 5,716,397; 5,607,471; 5,593,424; 5,376,112; 5,306,296; 5,163,954; 5,104,407; 5,064,431; 5,061,277; 4,917,698; 4,489,446; 4,290,151; 4,164,046; 4,042,979; and 3,656,185. Each and every one of the references cited above is hereby incorporated by reference into this application in their entireties to better describe the state of the art.
During conventional heart valve repair, annuloplasty rings, such as the CARPENTIER-EDWARDS CLASSIC(copyright) annuloplasty ring, have been used to provide support for the repaired native heart annulus and to remodel the annulus into its proper shape and configuration after valve repair. Like most others, the CARPENTIER-EDWARDS CLASSIC(copyright) annuloplasty rings are rigid structures designed to encircle the entire native valve annulus, thus forming a nearly complete circumference at the annular level. The shape of the ring is designed to simulate the shape and configuration of a normal valve. Thus, the abnormally shaped valve, which has undergone repair, can be transformed into a valve with a normal shape and configuration through the incorporation of the annuloplasty device.
Conventional annuloplasty rings are secured to the native annulus by sutures that are placed through the native heart annulus and through the conventional annuloplasty ring. This procedure remodels the valve annulus and prevents post-operative dilation of the annulus, which could lead to breakdown of the repair.
Conventional annuloplasty rings have a number of disadvantages. The most noteworthy technical disadvantage is that the annuloplasty ring must be sutured to the anterior part of the annulus, which is sometimes difficult to accomplish, as a significant portion of the anterior part of the annulus needs to be exposed for the suturing to be completed. This limitation of conventional annuloplasty rings is particularly apparent when minimally invasive surgical approaches are utilized, as exposure to the anterior part of the mitral valve annulus is generally restricted by this approach. Further, rigid, complete annuloplasty rings restrict the normal movement of the annulus of the heart at the point of implantation, limiting normal movement of the valve annulus throughout the cardiac cycle. An additional disadvantage associated with these conventional annuloplasty rings is that normal physiologic movement of the annulus is restricted.
Efforts to address some of the drawbacks associated with the previously discussed annuloplasty rings, have, in some cases, yielded rings which do not completely encircle the circumference of the annulus. One such ring which has been used for such procedures is the COSGROVE-EDWARDS(copyright) annuloplasty device. This annuloplasty ring incorporates a flexible piece of material for use only in the posterior part of the annulus for reinforcement. Although some of the drawbacks associated with the CARPENTIER-EDWARDS CLASSIC(copyright) style rings are obviated by COSGROVE-EDWARDS(copyright) annuloplasty device, these devices still have not proved to be an optimum solution for the cardiac surgeon.
As will be more fully addressed infra, the COSGROVE-EDWARDS(copyright) annuloplasty device is different from the instant invention because it: (1) is made entirely of a very flexible material, while the instant invention provides a semi-rigid annuloplasty device to support a repaired annulus in a fixed or semi-fixed position; (2) the present invention contains a support member constructed from a shape memory substance such as NITINOL(copyright), so as to be able to return to its original dimensions after deformation; and (3) does not attach to the anterior mitral valve annulus to permit remodeling in the anterior-to-posterior dimension.
Another such annuloplasty device which has been used for such procedures is the CARPENTIER-EDWARDS PHYSIO(copyright) annuloplasty ring. This annuloplasty device is a complete ring which incorporates a flexible piece of material which is attached to the entire annulus of the valve. Although some of the drawbacks associated with the CARPENTIER-EDWARDS CLASSIC(copyright) style rings are obviated by CARPENTIER-EDWARDS PHYSIO(copyright) annuloplasty ring, this device has failed to offer a solution to all of the aforementioned problems associated with annuloplasty rings currently available.
As will be more fully illustrated infra, the CARPENTIER-EDWARDS PHYSIO(copyright) annuloplasty device is different from the instant invention because it: (1) is made entirely of a very flexible material, while the instant invention provides a semi-rigid annuloplasty device to support a repaired annulus in a fixed or semi-fixed position; (2) the present invention contains a support member constructed from a shape memory substance such as NITINOL(copyright), so as to be able to return to its original dimensions after deformation; and (3) requires attachment to the complete mitral valve annulus which is unnecessary and sub-optimal for minimally invasive approaches for heart valve surgery.
The instant invention provides a semi-rigid ring designed to attach to the anterior annulus as a key fixation point, providing anterior-posterior remodeling by its design. The semi-rigidity of the instant device, its shape, and the anterior annular fixation points are all necessary for simultaneously achieving good annular remodeling, physiologic movement of the valve annulus, and ease of implantation. Thus, the instant invention provides an apparatus that achieves all of the benefits of the conventional, complete annuloplasty ring, without unnecessary restriction of the valve annulus, and without the need for placing sutures along the entire circumference of the anterior annulus. A device according to the instant invention also achieves better annular remodeling than the COSGROVE-EDWARDS(copyright) annuloplasty device by providing significant anterior-to-posterior fixation and narrowing.
The present invention is directed to annuloplasty rings or devices for use in heart surgery. More particularly, the present invention discloses novel annuloplasty rings, devices and methods for their use in minimally invasive heart valve replacement or repair surgery. As used herein, the terms xe2x80x9cannuloplasty ringxe2x80x9d or xe2x80x9cannuloplasty devicexe2x80x9d are used interchangeably without regard to whether such device can or does form a closed ring or unbroken annulus. Thus, the annuloplasty device of the instant invention can be referred to as an annuloplasty ring, even though it does not form a closed ring or unbroken annulus.
One aspect of the present invention provides an annuloplasty device shaped and sized for attachment to an inner surface of an annulus. The terms xe2x80x9cheart valve annulusxe2x80x9d or xe2x80x9cnative annulusxe2x80x9d are intended to designate the anatomical annulus of the heart. The annuloplasty device of this particular aspect, comprises a semi-rigid oblong support member having a first end, a second end, a first surface, and a second surface, the first surface including a securing means for securing the first surface to the inner surface of the heart valve annulus, wherein the annuloplasty device is capable of being bent to conform to the inner surface of the annulus such that the first end does not contact the second end.
In a preferred embodiment of the invention, the semi-rigid oblong support member is manufactured from a shape memory substance such as NITINOL(copyright). Such a material provides the semi-rigid properties of the annuloplasty device necessary to have sufficient flexibility to allow for changes in annular geometry during the cardiac contraction, while ensuring that the device returns to its original shape in an unstressed condition during cardiac relaxation.
In another aspect of the present invention, the annuloplasty device, which is shaped and sized for attachment to the inner surface of an annulus, comprises: a semi-rigid oblong support member covered on at least a portion of its length with a coating to produce a coated support member, the coated support member having a first end, a second end, a first surface, and a second surface, wherein the first surface includes securing means for securing the first surface to the inner surface of the heart valve annulus, and wherein the annuloplasty device is capable of being bent to conform to the inner surface of the annulus such that the first end does not contact the second end.
In a preferred embodiment of the invention, the annuloplasty device is shaped and sized for attachment to a inner surface of a heart valve annulus and is capable of being bent to conform to the inner surface of the heart valve annulus such that the first end does not contact the second end.
In still another preferred embodiment of the invention, the securing means comprises a plurality of apertures adjacent to the first surface of the annuloplasty device for allowing the passage of a securing means to secure the annuloplasty device to the inner surface of the annulus; the plurality of apertures may be distributed uniformly along the first surface. The securing means include sutures, adhesives, staples, and mechanical fasteners.
In yet another preferred embodiment of the invention, the annuloplasty device is made from bio-compatible materials.
In a further preferred embodiment of the invention, the semi-rigid oblong support member bends more readily in one direction than in another direction.
The instant invention also contemplates a kit comprising the annuloplasty device according to the invention, a holder to facilitate placing sutures through the annuloplasty device, and a set of template sizers to enable the surgeon to match the size of the native heart valve annulus and then to choose the appropriate size of the annuloplasty device.
Although the novel annuloplasty rings, devices and methods disclosed herein will be particularly useful in mitral valve replacement or repair surgery, it will become apparent to one of ordinary skill in the art, that the present invention will be useful in a myriad of applications, including but not limited to remodeling of the tricuspid valve.